This invention relates to apparatus for building a stream of fibrous material, and more particularly to improvements in apparatus which can be used with advantage in cigarette makers to form a continuous stream of comminuted tobacco leaves, substitute tobacco and/or reconstituted tobacco.
A tobacco stream is formed by drawing fragments of tobacco leaves from a magazine or another suitable source which is provided in or forms part of a distributor. The latter has means for delivering tobacco particles to one elongated reach of a foraminous belt conveyor to which the particles of tobacco are attracted by suction. The stream is thereupon trimmed to remove the surplus, and the resulting equalized stream is draped into a web of cigarette paper or other suitable wrapping material. The removed surplus is returned to the magazine of the distributor for readmission into the stream building zone.
It is further known to monitor the quantity of removed fibrous material prior to reintroduction into the distributor. Reference may be had to the published British patent application Serial No. 2 134 367 which discloses a plate-like deflector for the removed surplus. A drawback of monitoring means which is disclosed in the British application is that it does not furnish reliable signals as well as that the signals are too weak for satisfactory processing, e.g., to regulate the operation of the distributor in such a way that the quantity of the removed surplus can be held to a minimum.